1. Field of the Invention
This invention relates to a three-dimensional image special effect apparatus, and more particularly to a three-dimensional image special effect apparatus having a three-dimensional inputting apparatus.
2. Description of the Related Art
A three-dimensional image special effect apparatus is used to obtain such a special effect as to, for example, expand or contract or turn and move a special image fitted in another image on a monitor. In a three-dimensional image special effect apparatus of the type mentioned, a three-dimensional inputting apparatus such as a spherical track ball or a joy-stick in the form of a lever is used to operate the special image.
A three-dimensional inputting apparatus which employs a rotary ring in place of a track ball is also known and disclosed in Japanese Patent Laid-Open Application No. Heisei 2-282818 and Japanese Utility Model Laid-Open Application No. Heisei 2-143638, which correspond to U.S. patent application Ser. No. 512,860 filed Apr. 23, 1990, now abandoned.
By the way, various conditions of a special image such as a size or a border of the special image are given as parameters, and various effects can be achieved by suitably setting such parameters. The parameters are displayed on various menus, and for example, a track ball is manually operated to move a cursor on a menu to the position of a parameter and then a value of the parameter is set by manual operation of an inputting key such as a function key located separately from the track ball.
With the three-dimensional inputting apparatus described above, since the track ball for operating the cursor and the inputting key for setting a parameter are provided separately from each other, it is impossible to operate them at a time by one hand, and accordingly, a parameter setting operation is cumbersome.
It may be a possible idea to use a joy-stick as an inputting key. Where a joy-stick is employed, since a special image continues to move at a predetermined speed in a selected direction only by tilting a lever, operation is comparatively easy even to move a special image to a distance.
In contrast, where a track ball is employed, a special image is operated by rotating the track ball, and if rotation of the track ball is stopped, also the special image is stopped. Accordingly, in order to move the special image to a distance, the track ball must be manually operated several times to rotate the same in a same direction, which is very cumbersome. Further, since the amount of rotation of the track ball is not fixed in this instance, there is a problem in that the movement of the special image is not smooth.
A similar problem gives rise also to a rotary ring which is disposed for rotation around a track ball to operate a special image in a Z direction, that is, in a depthwise direction.
Further, a three-dimensional image special effect apparatus can represent in perspective representation, and when a special image is positioned at a distance in a depthwise direction as viewed on a screen of a monitor, the size of the special image is smaller than that when the special image is positioned nearer. Further, if input data to the three-dimensional inputting apparatus are same, the speeds of movement of a special image at a distance and another image in the neighborhood, that is, amounts of movement at the locations with respect to the input data, are equal to each other.
Accordingly, even if the amount of rotation of, for example, a track ball is equal, a special image at a distance as viewed on the screen of a monitor looks moving a small distance while another special image in the neighborhood looks moving a long distance. This makes an observer of the image have a perspective feeling.
However, with the three-dimensional image special effect apparatus of the type just described, when it is tried to move a special image at a distance to a predetermined position on the monitor, the track ball or some other manually operable member must be manually operated by a greater number of times than when it is tried to move another special image in the neighborhood. Further, a special image in the neighborhood may move from an end to another end of the screen only by manual operation of the track ball or a like element by a small amount. This may sometimes make a trouble.
A track ball is supported so that it can be rotated by a weak force in order to assure high operability and sensitivity. Consequently, when data other than three-dimensional data are inputted by way of, for example, ten keys, vibrations may be produced on an entire panel by a shock upon depression of the ten keys. Such vibrations may be transmitted to rotate the track ball so that inadvertent three-dimensional data may be inputted. In this instance, a special effect of an image will be disturbed.
Further, if the sensitivity of the track ball is raised, then also the influence of vibrations is increased. Therefore, the sensitivity must be restricted suitably.